Near field magneto-optical head made using wafer processing techniques

ABSTRACT

The method of making and self-aligning a magneto-optical head at a wafer level is as follows: A flat optical substrate is molded or heat pressed in batches as a wafer level to form the desired lens shapes. Coil cavities or depressions are simultaneously formed with the lens to accommodate the coil assembly. Conductive plugs are formed in proximity to the cutting lines, for wire bonding attachment to the coil. The plugs are filled with a conductive material such as copper. The plugs do not extend through the entire depth of the optical wafer, thus further facilitating the mass production of the integrated heads. The slider body wafer is formed from silicon or other appropriate material. The slider body wafer and the lens/coil wafer are bonded. Coils and pedestals are formed on the lens / coil plate using thin-film processing techniques. Reflective surfaces are deposited on the bottom surface of the substrate, opposite the lens. The mirror material around the pedestal areas and plugs is masked and removed. An alumina layer is then deposited to define the air bearing surface and the pedestal. Yokes are then formed by means of lithography and plating in the base and sides of the depressions to assume a desired shape. A series of alternating insulating layers and conductive coil layers is formed. A protective layer seals the coil assembly, and is lapped to correct the lens thickness and to provide proper focal plane.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates in general to data storage devices, and itparticularly relates to methods for mass producing a disk drive headwith a numerical aperture (NA) catadioptric focusing device, using waferprocessing techniques. The present invention further relates to acatadioptric focusing device with high numerical aperture (NA) for usein data storage systems such as optical and magneto-optical (MO) diskdrives.

2. Description of Related Art

In a MO storage system, a thin film read/write head includes an opticalassembly for directing and focusing an optical beam, such as a laserbeam, and an electro-magnetic coil that generates a magnetic field fordefining the magnetic domains in a spinning data storage medium or disk.The head is secured to a rotary actuator magnet and a voice coilassembly by a suspension and an actuator arm positioned over a surfaceof the disk. In operation, a lift force is generated by the aerodynamicinteraction between the head and the disk. The lift force is opposed byequal and opposite spring forces applied by the suspension such that apredetermined flying height is maintained over a full radial stroke ofthe rotary actuator assembly above the surface of the disk.

A significant concern with the design of the MO head is to increase therecording or areal density of the disk. One attempt to achieve objectiveis to reduce the spot size of the light beam on the disk. The diameterof the spot size is generally proportional to the numerical aperture(NA) of an objective lens forming part of the optical assembly, andinversely proportional to the wavelength of the optical beam. As aresult, the objective lens is selected to have a large NA. However,objective lenses with a large NA increase the spot aberration on thedisk, thus adversely affecting the MO head performance.

Another concern related to the manufacture of MO heads is the extremedifficulty and high costs associated with the mass production of theseheads, particularly where optical and electro-magnetic components areassembled to a slider body, and aligned for optimal performance.

SUMMARY OF THE INVENTION

One aspect of the present invention is to satisfy the long felt, andstill unsatisfied need for a near-field optical or MO disk data storagesystem that uses a catadioptric focusing device or lens with a highnumerical aperture (NA), which does not introduce significant spotaberration on the disk.

Another aspect of the present invention is to provide a focusing devicethat has generally flat surfaces that act as reference surfaces andfacilitate its manufacture and its assembly to the head.

The method of making and self-aligning the head at a wafer level is asfollows: A flat optical substrate is molded or heat pressed in batchesas a wafer level to form the desired lens shapes. Coil cavities ordepressions are simultaneously formed with the lens to accommodate thecoil assembly. Conductive plugs are formed in proximity to the cuttinglines, for wire bonding attachment to the coil. The plugs are filledwith a conductive material such as copper. The plugs do not extendthrough the entire depth of the optical wafer, thus further facilitatingthe mass production of the integrated heads. The slider body wafer isformed from silicon or other appropriate material. The slider body waferand the lens/coil wafer are bonded. Coils and pedestals are formed onthe lens / coil plate using thin-film processing techniques. Reflectivesurfaces are deposited on the bottom surface of the substrate, oppositethe lens. The mirror material around the pedestal areas and plugs ismasked and removed. An alumina layer is then deposited to define the airbearing surface and the pedestal. Yokes are then formed by means oflithography and plating in the base and sides of the depressions toassume a desired shape. A series of alternating insulating layers andconductive coil layers is formed. A protective layer seals the coilassembly, and is lapped to correct the lens thickness and to provide theproper focal plane.

The focusing device includes an incident surface, a reflective surface,a focal pedestal, and a body. The incident surface is generally flat andis comprised of a central diffractive, optically transmissive surfaceand a peripheral surface. In one embodiment, the peripheral surface iscomprised of a reflective-diffractive surface, or alternatively, areflective-kinoform phase profile.

In use, an incident optical beam, such as a laser beam impinges upon thecentral surface, and is diffracted thereby. The incident laser beam canbe collimated, convergent or divergent. The laser beam passes throughthe transparent body, and impinges upon the reflective surface. Thelaser beam is then reflected by the reflective surface, through thebody, unto the peripheral surface. The laser beam is reflected andeither diffracted or refracted by the peripheral surface, as a focusedbeam, through the body, and is focused in a focal point located at, orin close proximity to an edge of the focal pedestal. The focal point islocated in very close proximity to the disk such that a localizedevanescent field or light interacts with disk, enabling data to betransduced to and from the disk.

BRIEF DESCRIPTION OF THE DRAWINGS

The features of the present invention and the manner of attaining them,will become apparent, and the invention itself will be understood byreference to the following description and the accompanying drawings,wherein:

FIG. 1 is a fragmentary perspective view of a data storage systemutilizing a read/write head according to the invention;

FIG. 2 is a perspective view of a head gimbal assembly comprised of asuspension, and a slider to which the read/write head of FIG. 1 issecured, for use in a head stack assembly;

FIG. 3 is an enlarged perspective view of a head showing a focusingdevice according to the present invention;

FIG. 4 is an exploded view of the head of FIG. 3, illustrating a sliderbody, and a lens coil plate;

FIG. 5 is a top plan view of the head of FIG. 3, shown assembled to areflective surface (i.e., mirror), a quarter-wave plate, an opticalfiber, coil and mirror wires, and the lens coil plate of FIG. 4;

FIG. 6 is a front elevational view of the head of FIG. 5, furtherillustrating a coil forming part of the lens / coil plate of FIG. 4;

FIG. 7 is a side elevational view of the head of FIGS. 5 and 6;

FIG. 8 is a fragmentary, top plan view of a lens / coil wafer, shownfrom the lens (or focusing device) side, on which a plurality of lens /coil plates of FIG. 4, are formed, and illustrating a plurality offocusing devices;

FIG. 9 is a fragmentary, bottom plan view of the lens coil wafer of FIG.8, shown from the coil side, and illustrating a plurality of coils;

FIG. 10 is a fragmentary, top plan view of a slider body wafercontaining a plurality of slider bodies shown in FIG. 4, for assembly tothe lens coil wafer of FIGS. 8 and 9;

FIG. 11 is a perspective, exploded view of another head design,illustrating a slider body in the process being assembled to anindividual focusing device made according to the present invention, anddetached from the lens / coil wafer of FIG. 8;

FIGS. 12 through 22 illustrate the process of manufacturing the head ofthe present invention; and

FIG. 23 is an enlarged, side elevational view of a catadioptric focusingdevice forming part of the write head of FIGS. 1 and 2, made accordingto the present invention.

FIG. 24 is an enlarged, side elevational view of another catadioptricfocusing device forming part of the read/write head of FIGS. 1 and 2,and made according to the present invention;

FIG. 25 is a top plan view of the catadioptric focusing devices of FIGS.23 and 24;

FIG. 26 is a bottom plan elevational view of the catadioptric focusingdevices of FIGS. 23 and 24;

FIG. 27 is an enlarged, side elevational view of yet anothercatadioptric focusing device forming part of the read/write head ofFIGS. 1 and 2, and made according to the present invention;

FIG. 28 is an enlarged, side elevational view of still anothercatadioptric focusing device forming part of the read/write head ofFIGS. 1 and 2, and made according to the present invention; and

FIG. 29 is an enlarged, side elevational view of another catadioptricfocusing device forming part of the read/write head of FIGS. 1 and 2,and made according to the present invention.

Similar numerals in the drawings refer to similar or identical elements.It should be understood that the sizes of the different components inthe figures may not be in exact proportion, and are shown for visualclarity and for the purpose of explanation.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 illustrates a disk drive 10 comprised of a head stack assembly 12and a stack of spaced apart magnetic data storage disks or media 14 thatare rotatable about a common shaft 15. The head stack assembly 12 isrotatable about an actuator axis 16 in the direction of the arrow C. Thehead stack assembly 12 includes a number of actuator arms, only three ofwhich 18A, 18B, 18C are illustrated, which extend into spacings betweenthe disks 14.

The head stack assembly 12 further includes an E-shaped block 19 and amagnetic rotor 20 attached to the block 19 in a position diametricallyopposite to the actuator arms 18A, 18B, 18C. The rotor 20 cooperateswith a stator (not shown) for rotating in an arc about the actuator axis16. Energizing a coil of the rotor 20 with a direct current in onepolarity or the reverse polarity causes the head stack assembly 12,including the actuator arms 18A, 18B, 18C, to rotate about the actuatoraxis 16 in a direction substantially radial to the disks 14.

A head gimbal assembly (HGA) 28 is secured to each of the actuator arms,for instance 18A. With reference to FIG. 2, the HGA 28 is comprised of asuspension 33 and a read/write head 35. The suspension 33 includes aresilient load beam 36 and a flexure 40 to which the head 35 is secured.

In general, the head 35 is formed of a slider body (or slider) 47secured to the free end of the load beam 36 by means of the flexure 40,and a lens / coil plate 1001 which is secured to the slider 47. The lens/ coil plate 1001 comprises a substrate 1003 on (or within) which acatadioptric focusing device or lens 50 is formed on a first (or upper)side 1004 (FIG. 4). With further reference to FIG. 23, the lens / coilplate 1001 further comprises a coil or coil assembly 64 secured to thepedestal edge 163 for generating a desired write magnetic field. As isschematically illustrated by a block drawn in dashed lines (FIG. 3), thecoil 64 is formed on (or within) a second (or bottom) side 1006 of thelens / coil plate 1001, opposite and in alignment with the focusingdevice 50.

With reference to FIGS. 3 through 7, the head 35 further includes anoptical beam delivery means, such as a waveguide or a fiber 48. Astationary or a micro-machined dynamic reflective surface, such as amirror 49 having mirror wires 49A, is secured to a trailing edge 55 ofthe slider 47 at a 45 degree angle relative to the optical beamemanating from the fiber 48, so as to reflect the optical beam onto thefocusing device 50, in order to transduce data to and from a storagemedium 61 (FIG. 23).

The slider body 47 can be a conventional slider or any other suitableslider. In the present illustration, the slider body 47 includes a fiberchannel 1048 for receiving the optical fiber 48. Though the fiberchannel 1048 is illustrated as being centrally located, i.e., along agenerally central plane, relative to the slider body 47, it should beunderstood that the location of the fiber channel 1048 can be offsetwith respect to the central plane.

The slider body 47 further includes an optical opening 1050, which inthis example, extends from, and is wider than the fiber channel 1048.The optical opening 1050 is formed in the slider trailing edge 55. Theslider body 47 also includes two quarter-wave plate notches 1051 formedsymmetrically in two opposite sides of the slider body 47, within theoptical opening 1050. The quarter wave-plate notches 1050 cooperate toreceive and retain a quarter wave-plate or any other suitable opticalcomponent 1052 (FIGS. 5-7) that assist in guiding and focusing anoptical beam 135 (FIG. 23) emanating from the optical fiber 48.

A sloped surface 1049 can be formed on one or both sides of the trailingedge 55 relative to the optical opening 1050, in order to support themirror 49 at the desired angle, for reflecting the optical beam 135 fromthe fiber 48, through the quarter-wave plate, the focusing device 50,and the coil assembly 64, unto the disk 61 (FIG. 23). As illustrated inFIG. 23, the optical opening 1050 is formed through the entire height ofthe slider body 47, which facilitates the wafer level, mass productionof the slider body 47.

Optionally, an adhesive relief channel 1052A, shown in dashed lines inFIG. 3, is formed in the upper surface of the slider body 47,transversely, i.e., at an angle, relative to the fiber channel 1048. Theadhesive relief channel 1052A is preferably deeper than the fiberchannel 1048, so that excess adhesive flows within the adhesive reliefchannel 1052A, and is thus prevented from overflowing into the opticalopening 1050 and interfering with the optical path of the optical beam135. The tip of the fiber optic 48 projects within the optical opening1050. It should be clear that other channels and openings can bepatterned within the slider body 47, for example to receive opticalcomponents, including but not limited to lenses, beam splitters, etc. toenhance the optical performance of the head 35.

The lens / coil plate 1001 is secured to the slider body 47 such thatthe focusing device 50 (or lens) is positioned substantially underneaththe optical opening 1050, in optical alignment with the optical fiber48, the mirror 49, the quarter-wave plate 1052, and the coil assembly64.

Two contact pads 64A are formed in the side of the substrate 1003, asdescribed below, for connection to coil wires 64W. Wire traces 64Tconnect the coil assembly 64 and the contact pads 64A. The coil wires64W conduct an electrical current through the coil assembly 64 forenergizing it.

FIG. 11 illustrates another head 35A which is basically similar infunction to the head 35. The head 35A includes a slider body 47A that issimilar to the slider body 47, with the exception that the slider body47A includes an opening 1050A for receiving a lens / coil plate 1001A,within which the focusing device 50 and the coil assembly 64 are formedaccording to the present invention. According to this design, the lens /coil plate 1001A is individually fitted within the opening 1050A andsecured to the slider body 47A, for example by means of epoxy.

FIG. 8 illustrates a lens / coil wafer 1100, shown from the lens side,on which a plurality of lens / coil plates 1001 are formed. FIG. 9 is abottom plan view of the lens coil wafer 1100 of FIG. 8, shown from thecoil side, and illustrating a plurality of coils 64. By thin-film waferprocessing of the lens / coil plate 1001, enables the mass producing andalignment of the lenses 50 and the coil assemblies 64.

FIG. 10 illustrates a slider body wafer 1147 containing a plurality ofslider bodies 47. The slider body wafer 1147 is assembled to the lenscoil wafer of 1100 of FIGS. 8 and 9, by superimposing and aligning theslider body wafer 1147 on the upper surface of the lens coil wafer of1100 (shown in FIG. 8). Once the two wafers 1147 and 1100 are secured,for example by means of epoxy or sonic or anodic bonding, the wafers1147 and 1100 are sliced into individual, pre-aligned heads 35, alonglines 1110 (shown in dashed lines). The coil wires 64W are thenconnected to the contact pads 64A, and each head is then fitted with anoptical fiber 47, a mirror 49 and a quarter wave-plate 1052.

The method of making and self-aligning the head at a wafer level(withoutthe optical fiber 47, mirror 49, or quarter wave-plate 1052) will now beexplained in connection with FIGS. 12 through 22.

A flat glass (or optical) substrate or sheet is molded or pressed eitherindividually or in batches as a wafer level, as shown for example inFIGS. 15 through 18, to form the lens shapes illustrated, for example inFIGS. 19 through 22. Other lens shapes, for example shown in FIG. 23 canalso be formed. If the lenses 50 (or lens caps 1150) were not formed aspart of the optical substrate used as part of the final product, the UVcurable lens caps 1150 are attached to the optical substrate (See FIGS.21 and 22) by means of epoxy and UV cured to the optical substrate1110A.

Alternatively, and as illustrated in FIGS. 19, 20, and 23, the lenspatterns 1150A, 130, 200, 201, 202 are heat pressed or molded. The lenspatterns-can also be formed by photo polymer deposition, forming andetching including gray scale masking. In the embodiment shown in FIG.23, the lens surface is substantially flat.

Coil cavities 64C are simultaneously formed with the lens patterns(FIGS. 19, 21), to accommodate the coil assembly 64. Conductive plugs orvias 1125 (FIG. 19) are formed in proximity to the cutting lines 1110,for wire bonding attachment to the coil 64. The plugs 1125 are filledwith a conductive material such as copper. The plugs 1125 have an arcshaped cross section, for preventing the copper filling from beingdetached or removed from the plugs 1125 when the wafers are sliced intoindividual heads 35. In a preferred embodiment, the plugs 1125 do notextend through the entire depth of the optical wafer, thus furtherfacilitating the mass production of the integrated heads 35.

The slider body wafer 1147 is formed from silicon for example (see FIGS.10, 12, 13). It should be noted that the etching, machining or formingof the fiber channel 1048 can be done subsequent to bonding the sliderbody wafer 1147 to the lens/coil wafer 1110. The slider body wafer 1147and the lens/coil wafer 1110 are bonded, using known or availabletechniques such as: anodic bonding, diffusion, glass bonding using forexample glass frift, or adhesive bonding for example epoxy.

A coil 1164, and a pedestal 110 shown in FIGS. 14 and 23 are formed onthe lens / coil plate 1001 using thin-film processing techniques.Reflective surfaces or mirrors 1105 are deposited on the bottom surfaceof the substrate 1110, opposite the lens 50. The mirror material aroundthe pedestal 110 areas and plugs 1125 is masked and removed.

Alumina or a similar type first transparent material layer 1130 is thendeposited to define the air bearing surface and the pedestal 110.Depressions or cavities 64C (See also FIG. 19) are then formed in thealumina layer around the pedestal 110, within which depressions theconductive coils 1164 will be formed.

Yoke or flux gather gathering layers 1133 are then formed by means oflithography and plating in the base and sides of the depressions toassume a desired shape. In a preferred embodiment, the yoke 1133 coversthe conductive coils 1164 so as to optimize the collected magneticfield.

An insulating layer 1155 is formed on the yoke 1133, and a first layerof conductive coils 1164 are deposited on the insulating layer 1155 bymeans of, for example, lithography and plating. An insulating layer isthen formed on the first layer of conductive coils 1164, and a secondlayer of conductive coils 1164 is deposited thereon. These steps arerepeated until the desired number of coil layers is reached.

A protective layer 1160 of insulating and transparent material isdeposited on the final coil layer to provide a protective seal to thecoil assembly 64. The protective layer 1160 is then lapped to correctthe lens thickness and to provide the proper focal plane 163 (FIG. 23).

An alternative approach to forming the coil cavity 64C is to heat pressit into the glass wafer as shown in FIGS. 15, 16, 18, 19, 21. Such heatpressing step will precede the step of depositing the reflectivesurfaces 1105.

The air bearing surface (ABS) of the slider 47 is then formed, by forexample etching, into the protective layer 1160. The heads 35 are thensliced or etched away from the wafer, into individual heads. The quarterwave plate, mirror, wires, and optical fiber are then assembled to thehead 35 and aligned, to complete the manufacture of the head 35. Thehead 35 is then assembled to the suspension as is known in the field toform the HGA 28 (FIG. 2).

The details of the focusing device 50 will now be described withreference to FIG. 23. The focusing device 50 includes an incidentsurface 100, a reflective surface 105, a focal pedestal 110, and a body115. The incident surface 100 is generally flat and is comprised of acentral diffractive, optically transmissive surface 130 and a peripheraldiffractive or kinoform phase profile 133. In a preferred embodiment,the body is an optically transparent lens body, and the incident surface100 is formed on a first side of the body 115. The reflective surface115 is formed on a second side of the body 115, such that the first andsecond sides are preferably, but not necessarily, oppositely disposed.The focal pedestal 110 is formed on the same side as the reflective 105.

In use, an incident optical beam, such as a laser beam 135 impinges uponthe central surface 130, and is diffracted thereby. The incident laserbeam 135 can be collimated, convergent or divergent. The laser beam 135passes through the transparent body 115, and impinges upon thereflective surface 105. The laser beam is then reflected by thereflective surface 105, through the body 115, unto the peripheralsurface 133. The laser beam 135 is reflected and also diffracted orrefracted by the peripheral surface 133 as a focused beam 135A, throughthe body 115, and is focused in a focal point 162 located at, or inclose proximity to an edge 163 of the focal pedestal 110.

The focal point 162 is located in very close proximity to the disk 61such that a localized evanescent field or light 170 interacts with disk61, enabling data to be transduced to and from the disk 61.

The focused beam 135A defines an angle of incidence θ with a centralplane P. It should be clear that the angle of incidence θ is greaterthan the angle of incidence θ had the optical beam 135 not undergone thesequence of reflections and diffractions as explained herein. As aresult, the NA of the focusing device 50 exceeds that of a conventionalobjective lens, as supported by the following equation:

    NA=n.sinθ,

where n is the index of refraction of the lens body 115. According tothe present invention, it is now possible to select the lens body 115 ofa material with a high index of refraction n, in order to increase NA.

Though exemplary dimensions of the focusing device 50 are illustrated inFIG. 23, within an acceptable range, it should be clear that thesedimensions can be scaled as desired for the intended applications.

In one embodiment, the peripheral surface is formed of kinoform phaseprofile 133, which includes a pattern of refractive profiles i.e., 200,201, 202. While only three refractive profiles are illustrated, itshould be understood that a greater number of refractive profiles can beselected. The pattern of refractive profiles 200, 201, 202 is coatedwith a reflective surface 210. In another embodiment, the peripheralkinoform phase profile 133 can be replaced with an appropriatediffractive grating or profiles, or with an appropriate lens structuresuch as a Fresnel lens.

The focal pedestal 110 is formed integrally with lens body 115, andextends below the reflective surface 105.

With more particular reference to FIGS. 25 and 26, the focusing device50 is generally cylindrically shaped, and is formed within a substrate225. The transmissive surface 130 (FIG. 25) concentric relative to, andis disposed within the reflective surface 210. The transmissive surface130 can simulate holographic or virtual flat, spherical, conical orother suitable diffractive surfaces 233 (shown in dashed lines in FIG.23), while retaining its generally flat configuration. The reflectivesurface 210 is ring shaped. In an alternative design, the kinoform phaseprofile can simulate an aspherical refractive or diffractive surface 234(shown in dashed lines in FIG. 23), while 26 retaining its generallyflat configuration.

The focal pedestal is generally cylindrically shaped, and is co-axially,and concentrically disposed relative to the reflective surface 105. Inan alternative embodiment, the incident surface includes an alignmentring 237 (shown in dashed lines), to assist in the alignment of thefocusing device 50 during assembly to the slider 47.

The focusing device 50 can be made using molding, etching, or othersuitable manufacturing techniques. The flatness of the incident surface100 allows wafer processing techniques to be used to mass assemble alens wafer in which a plurality of focusing devices 50 are formed, to aslider wafer in which a plurality of sliders 47 are formed.

Using the present focusing device 50, it is possible to reduce the spotsize on the disk 61 to less than 0.3 microns. The focusing device 50 canbe made of any suitable transparent material, including but not limitedto glass, plastic, etc.

FIG. 24 illustrates another catadioptric focusing device 400 accordingto the present invention. The focusing device 400 is generally similarin function and design to the focusing device 50, and has its incidentsurface 100A comprised of a peripheral kinoform phase profile 133A. Theperipheral kinoform phase profile 133A is formed of a reflective surface210 and a pattern of concentric binary refractive profiles i.e., 420,421, 422. The resolution of the refractive profiles 420, 421, 422 canvary, for example increase, in order to obtain a more precise controlover the diffraction of the laser beam 135A.

FIG. 27 illustrates another catadioptric focusing device 450 accordingto the present invention. The focusing device 450 is generally similarin function and design to the focusing devices 50 and 400, and has itsincident surface 100B comprised of a peripheral kinoform phase profile133B. The peripheral kinoform phase profile 133B is formed of areflective surface 210 and a pattern of concentric binary refractiveprofiles i.e., 200, 201, 202 or 420, 421, 422. Whereas in the focusingdevices 50 and 400, the incident surfaces 100, 100A, respectively areformed integrally with the lens body 115, the incident surface 100B isformed of a separate plate that is secured to the lens body 115 along agenerally flat surface 455.

Another optional distinction between the focusing device 450 of FIG. 27and the focusing devices 50 and 400 of FIGS. 23 and 24, respectively, isthat the focal pedestal 110 can be made of a separate plate that issecured to the lens body 115 along a central, non-reflective surface 463of the bottom of the lens body 115.

FIG. 28 illustrates another catadioptric focusing device 475 accordingto the present invention. The focusing device 475 is generally similarin function and design to the focusing devices 50, and has its incidentsurface 100C comprised of a peripheral kinoform phase profile 133C. Theperipheral kinoform phase profile 133C includes a pattern of refractiveprofiles i.e., 200C, 201C, 202C that are similar in function to therefractive profiles i.e., 200, 201, 202.

FIG. 29 illustrates another catadioptric focusing device 485 accordingto the present invention. The focusing device 485 is generally similarin function and design to the focusing devices 50, and has its incidentsurface 100D comprised of a peripheral kinoform phase profile 133D. Theperipheral kinoform phase profile 133D includes a pattern of refractiveprofiles i.e., 200D, 201D, 202D that are similar in function to therefractive profiles i.e., 200,201, 202.

It should be understood that the geometry, compositions, and dimensionsof the elements described herein may be modified within the scope of theinvention and are not intended to be the exclusive; rather, they can bemodified within the scope of the invention. Other modifications may bemade when implementing the invention for a particular environment. Theuse of the focusing device is not limited to data storage devices, as itcan be used in various other optical applications, including but notlimited to high resolution microscopy, surface inspection, and medicalimaging.

What is claimed is:
 1. A method of making a head comprising:forming aplurality of lens patterns in a first side of an optical substrate;forming a plurality of coil depressions in a second side of said opticalsubstrate; forming a plurality of slider bodies in a slider bodysubstrate; securing said slider body substrate to said first side ofsaid optical substrate; and forming a plurality of coil assemblies insaid plurality of coil depressions.
 2. A method according to claim 1,wherein forming said plurality of coil assemblies in said plurality ofcoil depressions includes forming coil assemblies opposite to, and inoptical registration with said lens patterns.
 3. A method according toclaim 2, wherein forming said coil assemblies includes forming a fluxgathering layer in said coil depressions.
 4. A method according to claim3, wherein forming said coil assemblies includes forming an insulatinglayer on said flux gathering layer; andforming a layer of conductivecoils on said insulating layer.
 5. A method according to claim 1,wherein forming said coil depressions includes forming said coildepressions simultaneously with said lens patterns.
 6. A methodaccording to claim 1, wherein forming said lens patterns includes usingany one or more methods: heat pressing, molding, photo polymerdeposition, or gray scale masking.
 7. A method according to claim 1,wherein forming said lens patterns includes forming substantially flatlens patterns.
 8. A method according to claim 1, further includingforming cutting lines along which said lens patterns can be individuallyseparated.
 9. A method according to claim 8, further including forming aplurality of plugs in proximity to said cutting lines for electricalattachment to said coil assemblies.
 10. A method according to claim 9,further including filling said plugs with a conductive material.
 11. Amethod according to claim 10, wherein forming said plugs includesshaping said plugs to prevent detachment upon separation of said lenspatterns along said cutting lines.
 12. A method according to claim 1,further including forming a plurality of pedestals on said second sideof said optical substrate.
 13. A method according to claim 12 whereinsecuring said slider body substrate and said optical substrate includesbonding using any one or more methods: anodic bonding, diffusion, glassfrift, or adhesive bonding.
 14. A method according to claim 12, furtherincluding selectively depositing reflective surfaces on said second sideof said optical substrate, around said pedestals.
 15. A method accordingto claim 12, further including lapping said second side to a desiredthickness to provide a desired focal plane.
 16. A method according toclaim 12, wherein said optical substrate is made of glass, and whereinforming said lens patterns and said coil depressions includes heatpressing said glass substrate.
 17. A method of making a headcomprising:forming a plurality of lens patterns in a first side of anoptical substrate; forming a plurality of coil depressions on a secondside of said optical substrate, forming a plurality of slider bodies ina slider body substrate; forming a plurality of pedestals on said secondside of said optical substrate; selectively forming a plurality ofreflective surfaces on said second side around said plurality ofpedestals; securing said slider body substrate to said first side ofsaid optical substrate; and forming a plurality of coil assemblies insaid plurality of coil depressions on said second side.
 18. A methodaccording to claim 17, wherein forming said lens pattern s include susing any one or more methods: heat pressing, molding , photo polymerdeposition, or gray scale masking.
 19. A method according to claim 17,wherein forming said lens patterns includes forming substantially flatlens patterns.
 20. A method according to claim 17, further includingforming cutting lines along which said lens patterns can be individuallyseparated;forming a plurality of plugs in proximity to said cuttinglines for electrical attachment to said coil assemblies, and fillingsaid plugs with a conductive material; and shaping said plugs to preventtheir detachment upon separation of said lens patterns along saidcutting lines.
 21. A method according to claim 17, further includingselectively depositing reflective surfaces on said second side of saidoptical substrate.
 22. A method according to claim 17 wherein formingsaid plurality of coil assemblies includes:forming a flux gatheringlayer in said coil depressions; forming an insulating layer on said fluxgathering layer; and forming a layer of conductive coils on saidinsulating layer.
 23. A method according to claim 17, wherein saidoptical substrate is made of glass, and wherein forming said lenspatterns and said coil depressions includes heat pressing said glasssubstrate.
 24. A method according to claim 17, wherein forming a lenspattern includes: forming a substantially flat incident surfacecomprised of a diffractive, optically transmissive surface and aperipheral diffractive and reflective surface; and forming asubstantially flat incident surface comprised of a flat diffractive,optically transmissive surface and a peripheral surface that includes akinoform phase profile.
 25. A method according to claim 17, whereinsecuring said slider body substrate and said optical substrate includesbonding using any one or more methods: anodic bonding, diffusion, glassfrift, or adhesive bonding.
 26. A method of making an optical devicecomprising:forming a plurality of lens patterns in a first side of anoptical substrate; forming a plurality of pedestals on a second side ofsaid optical substrate; selectively forming a plurality of reflectivesurfaces on said second side around said plurality of pedestals; forminga plurality of coil depressions in said second side; and forming aplurality of coil assemblies in said plurality of coil depressions. 27.A method according to claim 26, wherein forming a lens pattern includesforming a substantially flat incident surface comprised of adiffractive, optically transmissive surface and a peripheral diffractiveand reflective surface.
 28. A method according to claim 26, whereinforming a lens pattern includes forming a substantially flat incidentsurface comprised of a flat diffractive, optically transmissive surfaceand a peripheral surface that includes a kinoform phase profile.
 29. Amethod according to claim 26, wherein forming said lens patternsincludes using any one or more methods: heat pressing, molding, photopolymer deposition, or gray scale masking.
 30. A method according toclaim 26, wherein forming said lens patterns includes formingsubstantially flat lens patterns.
 31. A method according to claim 26,further including forming cutting lines along which said lens patternscan be individually separated.
 32. A method according to claim 31,further including forming a plurality of plugs in proximity to saidcutting lines for electrical attachment to said coil assemblies, andfilling said plugs with a conductive material.
 33. A method according toclaim 32, wherein forming said plugs includes shaping said plugs toprevent their detachment upon separation of said lens patterns alongsaid cutting lines.
 34. A method according to claim 26, furtherincluding selectively depositing reflective surfaces on said second sideof said optical substrate.
 35. A method according to claim 26 whereinforming said plurality of coil assemblies includes:forming a fluxgathering layer in said coil depressions; forming an insulating layer onsaid flux gathering layer; and forming a layer of conductive coils onsaid insulating layer.
 36. A method according to claim 26, furtherincluding lapping paid second side to a desired thickness to provide adesired focal plane.
 37. A method according to claim 22, wherein saidoptical substrate is made of glass, and wherein forming said lenspatterns and said coil depressions includes, heat pressing said glasssubstrate.